It is known to provide a seat belt system which is connected to the door so that movement of the door between the open and closed positions will automatically move the seat belt between a restraining position about the occupant when the door is closed and a position away from the occupant when the door is open to permit occupant ingress and egress.
The prior art has recognized that such passive seat belt systems may employ a retractor mounted upon the door and having a vehicle inertia sensitive locking mechanism adapted to lock up the retractor in response to the onset of predetermined vehicle acceleration. The prior art has also recognized that a rapid opening movement of the door may cause the retractor to experience a sufficient level of acceleration to lock up the retractor. Accordingly, many prior art patents have disclosed various devices for entirely blocking out or merely desensitizing the inertia locking mechanism in response to actuation of the door latch or in response to sensing a door open condition.
It would be desirable to provide a door mounted seat belt retractor having an associated device for desensitizing the inertia locking mechanism independently of any inter-connection with the door latch or with a sensor for determining the position of the door.